Department of Biomedical Sciences, Section of Physiology, University of Modena and Reggio Emilia, I-41125 Modena, Italy.
Neurosci Lett. 2012 Jan 6;506(1):33-8. doi: 10.1016/j.neulet.2011.10.043. Epub 2011 Oct 21.
We studied the activity of single neurons in the pre-supplementary motor area (pre-SMA) of macaque monkeys as they performed two visuomotor tasks, called the visual fixation task and the visual fixation-blink task. Both tasks involved a sequence of three visual stimuli, red followed by yellow and green. The tasks differed in that the latter one had a gap within the period of the red stimulus, called a "blink". The tasks were performed in two modes, one of which included movements of both the arm and eye and the other of which involved only eye movements. In the arm-eye mode, the monkeys had to press a bar and fixate the red stimulus that appeared after bar press. To receive a reward, both the bar press and visual fixation had to be maintained until the green stimulus triggered bar release. In the eye mode, bar press and bar release were eliminated from the task. Of the 42 neurons active during the visual fixation task, 15 showed task-related activity in both arm-eye and eye modes, and our analysis focused on these cells. We found that the introduction of the blink in visual fixation-blink task abolished the task-related activity of these cells over the course of 2-4 trials. This finding suggests a role for the pre-SMA in reflecting progression of trials as an updating of motor instruction.
我们研究了猕猴补充运动前区（pre-SMA）中单神经元的活动，这些猴子在执行两个视觉运动任务时，分别称为视觉固定任务和视觉固定-眨眼任务。这两个任务都涉及三个视觉刺激，红色、黄色和绿色。任务的区别在于后者在红色刺激期间有一个间隙，称为“眨眼”。任务以两种模式执行，一种模式包括手臂和眼睛的运动，另一种模式仅涉及眼睛运动。在臂眼模式下，猴子必须按下一个杆并固定在按下杆后出现的红色刺激。为了获得奖励，必须保持杆按压和视觉固定，直到绿色刺激触发杆释放。在眼模式下，任务中消除了杆按压和杆释放。在视觉固定任务中活跃的 42 个神经元中，有 15 个在臂眼和眼模式下都表现出与任务相关的活动，我们的分析集中在这些细胞上。我们发现，在视觉固定-眨眼任务中引入眨眼会在 2-4 次试验过程中消除这些细胞的与任务相关的活动。这一发现表明 pre-SMA 在反映试验进展方面发挥作用，作为运动指令的更新。
